Gas Seal Column Pump for Elevated Temperature Applications

ABSTRACT

The gas seal column pump may comprise a pump drive, a gas seal column with a corrosion resistant telescoping liner, a seal gas control box, and a pump. A drive motor of the pump drive, the gas seal column, and the pump may comprise a sealed, vertically-oriented, pumping system where the gas seal column is operable to replace mechanical seals around a drive shaft that couples the drive motor to the pump. A pressurized seal gas pumped into the gas seal column may displace corrosive fumes and the product being pumped. An unsealed pump drive motor may be used for certain applications. The vertical length of the telescoping liner may be controlled to mitigate interference with pump operation. Responsive to inputs from the level sensors, a seal gas control box may regulate the pressure of the seal gas using a plurality of valves.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, but otherwise reserves all copyright rightswhatsoever.

BACKGROUND

In the pumping world dominated by horizontal pumps of all differentstyles, mechanical seals or shaft packing glands are the mosttroublesome and highest maintenance cost items over all other pumpcomponents.

Vertical pumps that have high temperature applications are known.However, such pumps typically apply standard pump components that do notpermit elongation or shortening through a telescoping feature.

SUMMARY OF THE INVENTION

The answer to eliminating these problems and their associated expensesis to remove both components and reposition the pump componentsvertically with a gas seal column encasing a drive shaft between a drivemotor and a pump. The drive motor may be sealed or unsealed, and the gasseal column and the pump may form a sealed unit that is pressurized forproduct containment. However, elevated temperature applications mayrequire a corrosion resistant lined metallic outer column or for specialapplications a metallic outer column supporting a telescoping hightemperature corrosion resistant liner described herein.

These numerous benefits, and other numerous benefits listed herein, maybe realized by utilizing the invention:

-   -   With a gas seal column there is no contact between rotating and        stationary components of the pump, thereby allowing for a        continuous run dry capability. Run dry capability may result in        the elimination of friction, heat, mechanical wear, power loss,        high initial cost, installation cost, replacement cost, and        collateral damage cost of mechanical seal and packing when they        inevitably fail and significantly reduces the possibility of        product leakage requiring cleanup and reporting to an oversight        or authoritative body.    -   A gas seal column, through the use of product monitoring        sensors, also allows for continuous timely product control,        reporting, operator alerting, and, if needed, controlled        automatic shutdown of pumping operations to prevent equipment        and collateral damage. In contrast, seal and packing failures        may announce themselves with a large puddle on the floor.    -   Combining a gas seal column with a drive motor and sealing the        gas seal column and the pump components of the pumping system        together allows for:        -   Improved internal atmosphere control to prevent corrosion of            internal components, especially motor bearings.        -   Improved product control with essentially no possibility of            product escaping the containment envelope, possibly causing            employee injury or nearby equipment damage.        -   In many cases eliminating the cost of a bearing pedestal by            using a sealed extended shaft motor with a corrosion            resistant sleeve to protect the extended motor shaft.        -   Operation at higher temperatures may be accomplished by            utilizing a corrosion resistant liner inside a metallic            support column similar to lined pipe and pumps currently on            the market, and for special application, by utilizing a            structural metal column with a telescoping corrosion            resistant liner as herein described.        -   In cases where a monolithic corrosion resistant pump column            cannot be used, the liner or a telescoping liner can be            used.

Considering all of the above it can easily be expected that the totallife cycle cost of a gas seal column pump, especially a structural metalcolumn with a telescoping corrosion resistant liner optimized for use inelevated temperature situations, will be significantly lower than for asimilar performing mechanical seal or packing pump.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain illustrative embodiments illustrating organization and method ofoperation, together with objects and advantages may be best understoodby reference to the detailed description that follows taken inconjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view of a sealed gas seal column pumpconsistent with certain embodiments of the present invention andillustrating a pump drive, a gas seal column, a seal gas control box,and a pump.

FIG. 2 is a cross-sectional view of a sealed gas seal column pumpconsistent with certain embodiments of the present invention andillustrating a bearing shaft adapter used in conjunction with a pumpdrive, a gas seal column, and a pump.

FIG. 3 is a cross-sectional view of a sealed gas seal column pump havinga telescoping liner consistent with certain embodiments of the presentinvention and illustrating a pump drive, a gas seal column with atelescoping liner, and a pump.

FIG. 4 is a cross-sectional view of a ‘Gas Seal Column’ pump consistentwith certain embodiments of the present invention and illustrating a GasSeal Column and a pump joined together as a sealed enclosure. The GasSeal Column may be connected to an unsealed pump drive motor and a sealgas control box.

DETAILED DESCRIPTION

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and will herein be described indetail specific embodiments, with the understanding that the presentdisclosure of such embodiments is to be considered as an example of theprinciples and not intended to limit the invention to the specificembodiments shown and described. In the description below, likereference numerals are used to describe the same, similar orcorresponding parts in the several views of the drawings.

The terms “a” or “an”, as used herein, are defined as one or more thanone. The term “plurality”, as used herein, is defined as two or morethan two. The term “another”, as used herein, is defined as at least asecond or more. The terms “including” and/or “having”, as used herein,are defined as comprising (i.e., open language). The term “coupled”, asused herein, is defined as connected, although not necessarily directly,and not necessarily mechanically.

Reference throughout this document to “one embodiment”, “certainembodiments”, “an embodiment” or similar terms means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the presentinvention. Thus, the appearances of such phrases or in various placesthroughout this specification are not necessarily all referring to thesame embodiment. Furthermore, the particular features, structures, orcharacteristics may be combined in any suitable manner in one or moreembodiments without limitation.

The gas seal column pump (hereinafter “invention”) may comprise a pumpdrive motor having a sealed housing or an unsealed housing, a gas sealcolumn, a seal gas control box, and a pump. The pump drive may comprisea pump drive motor and a cooling fan. The pump drive motor may comprisea drive shaft that is extended to reach the pump through the gas sealcolumn. The pump drive motor may further comprise a pressurized housingor an unpressurized housing. The cooling fan may be mounted to the pumpdrive motor externally to cool the pump drive motor instead of driving afan from an extension of the drive shaft of the pump drive motor throughthe top of the pump drive motor. Alternatively, ducted cooling from aremote source may be used to cool the pump drive motor.

The seal gas may be clean and pressurized and may be sourced locally orremotely. The first choice for the seal gas would be clean air that isfree of corrosive fumes. Alternatively, a specialized gas may be used ifair is incompatible with a product being pumped. If the seal gas that isselected to be used cannot be released to the environment after usebecause of cost, toxicity, contamination, or other reasons then the sealgas may be directed to a local gas treatment system or collected in atank for later treatment. After treatment, the seal gas may be reused ordisposed of.

The gas seal column may be operable to encase the drive shaft componentof the pumping system and may function as a replacement for mechanicalseals and packing by using pressure of the seal gas to control a productlevel within the gas seal column, during startup, when pumping, duringshutdown, or in standby when gas seal column controls are activated.

The gas seal column may comprise a top mounting panel at the top end ofthe gas seal column. A circular groove in the top mounting panel maycapture a first O-ring which is operable to pressure seal the interfacebetween the pump drive motor and the gas seal column.

An inlet pipe connection and an outlet pipe connection located in theupper quarter of the gas seal column may allow the seal gas to flow inand out of the gas seal column. A purge gas inlet valve and a purge gasdischarge valve may control the flow of the seal gas.

The gas seal column may or may not comprise as assembly of SplashQuieting Discs (SQDs) and Anti-Rotation Panels (ARPs). Each SQD is astructural element that may be formed as a disc with an outside diameterthat is an easy slip fit into the seal column and with an insidediameter slightly larger than the shaft that will pass through it toensure no contact with the shaft. The SQDs may be perforated as neededto allow for passage of the product. While described as a disc, each SQDmay function as a porous horizontal barrier to the product andconsequently may be made in a large variety of different structuralconfigurations, including, but not limited to, discs, coils, cylinders,mesh, or other structures, that still fall within the spirit of theinvention.

ARPs are vertical structural elements that may have a width the same asthe outside radius minus the inside radius of the SQDs.

SQDs may be attached to and separated by ARPs and positioned andfastened at a right angle to the flat plane of the SQD, as shown inFIGS. 1 and 4. The number of ARPs and the angular separation on the faceof the SQDs may be determined by the application. Three sets of ARPs maybe of the same height and fastened at each end to an SQD. The bottom setof ARPs may be fastened only to the underside of the bottom SQD and theheight is adjusted to suit that particular column length. For ease ofmanufacture the SQDs and the ARPs may be assembled and fastened togetheroutside the gas seal column. The entire assembly may be combined througha slip fit into the column and should be secured to prevent movement ofeach element of the assembly.

In an application where the product supply source and the productdischarge outlet are located above the pump drive motor, when the pumpdrive motor switches from ‘on’ to ‘off, the product being pumped maysurge into the column in a turbulent manner.

With an SQD and ARP assembly in place, the product being pumped mayrapidly fill the cavity below the bottom SQD. The product will graduallyfill up the cavity below the second SQD, below the third SQD, and so onbecause of the small clearances between the SQD, the column and theshaft, and depending upon the type and number of perforations in theSQD. In this way the SQDs prevent splashing damage to the pump drivemotor and allow time for the product control system to react as neededto minimize or eliminate damage to the pump drive motor.

The gas seal column may comprise a plurality of level sensors. Theplurality of level sensors may detect the product level within the gasseal column and may report the product level to the seal gas controlbox. Based upon input from the plurality of level sensors, the seal gascontrol box may be adapted to monitor the product level, may report theproduct level, may alert an operator, and may control the product levelof the product that may come into the gas seal column during operatingand standby conditions, when the seal gas control box is energized by apurge gas control switch. As a non-limiting example, the seal gascontrol box may be adapted to alert the operator by activating flashingindicators, sending text messages, pages, or emails, sounding audibletransducers, or combinations thereof if the product level exceeds apredetermined alert threshold. As a further non-limiting example, theseal gas control box may shut down the pump and possibly othercomponents if the product level exceeds a predetermined shutdownthreshold.

In an embodiment there may be four level sensors. The four level sensorsmay be equally spaced along the gas seal column. A first level sensormay be located at the lowest level of the gas seal column. A secondlevel sensor, a third level sensor, and a fourth level sensor may belocated above the first level sensor in that order, with the fourthlevel sensor being at the highest level within the gas seal column.

At pump start up, the purge gas control switch may be activated manuallyor automatically. Responsive to activating of the purge gas controlswitch, the seal gas control box may begin a low volume purge gas flowthroughout the system by opening a purge gas valve and leaving a firstgas valve and a second gas valve closed. In some embodiments, theopening and closing of the purge gas valve, the first gas valve, asecond gas valve, and the gas discharge valve may be controlled byrelays or other controls located within the seal gas control box.

In some embodiments, the purge gas valve, the first gas valve, and thesecond gas valve may provide differing flow rates of the seal gas whenin the open state. The differing flow rates may result in differingpressures applied to the product within the gas seal column. Thesmallest flow rate, and therefore the lowest pressure on the productwithin the gas seal column, may result from having only the purge gasvalve open. The highest flow rate, and therefore the highest pressure onthe product within the gas seal column, may result from having the purgegas valve, the first gas valve, and the second gas valve all open.Because the seal gas may be introduced into the top of the gas sealcolumn, the pressure applied to the product from the seal gas may workto force the product level down.

The seal gas control box may become aware that the product has enteredthe gas seal column when the first level sensor detects the product andopens the purge gas valve. If the product is detected by the secondlevel sensor, the seal gas control box may attempt to stop the productfrom rising further in the gas seal column by increasing the pressure ofthe seal gas within the gas seal column. The seal gas control box mayopen the first gas valve, thus releasing a higher flow of the seal gasinto the gas seal column. If this works and the product level drops,then the second level sensor may reflect that the product is no longercontacting the second level sensor. However, the seal gas control boxmay retain the first gas valve in the open state. When the first levelsensor indicates that the product level has dropped below the firstlevel sensor, the seal gas control box may close the first gas valve,the purge gas valve, and the gas discharge valve.

Alternatively, if the product level continues to rise above the secondlevel sensor and is detected by the third level sensor, the seal gascontrol box may activate and latch a relay that opens the second gasvalve, thus releasing an even higher flow of gas into the gas sealcolumn to further increase gas pressure to push the product down in thegas seal column. The seal gas control box may additionally be adapted tosend an alert to the operator reporting that the product is appearing ata higher level in the gas seal column than is normally expected. Thehigher level of gas flow will continue until the product is driven downto the first level sensor which will open and deactivate the two latchedrelays that will then close the first gas valve, the second gas valve,the purge gas valve, and the gas discharge valve.

Alternatively, if the product level continues to rise and is detected bythe fourth level sensor, the seal gas control box may be adapted toinitiate a controlled, complete shutdown of the system and close allvalves to maintain the sealed integrity of the total pump housing and toprevent equipment damage or other collateral damage from occurring. Thisshutdown sequence allows the operator to investigate what is causing thecondition and to correct the problem.

The first level sensor may be located slightly above the minimum priminglevel for the pump. When the pump is stopped, inlet or outlet conditionsmay cause the product to rise or drop in the gas seal column. A rise inthe product level may be controlled as previously described. Responsiveto a drop in the product level below the first level sensor, the sealgas control box may deactivate the relay that holds the purge gas valveopen. Closing the purge gas valve may stop purge gas flow until theproduct rises to reach the first level sensor. The seal gas control boxmay function in this manner whether the pump is operating or in standbymode as long as the seal gas control box is activated.

The description of sensing and control presented herein is by way ofillustration only. There are many other sensing and control techniquesthat may be applied which a person having ordinary skill in the art willrecognize as falling within the spirit and scope of the invention.

The pump illustrated is a centrifugal pump comprising a pump casing withan inlet and an outlet and an O-ring to seal a cover plate to the pumpcasing. The pump casing may be sealed to the gas seal column with secondO-ring, completing the seal for the entire assemblage. The drive motor,the gas seal column, and the pump may or may not comprise a single,sealed unit. In an embodiment, the drive motor may form a portion of thesingle, sealed unit, may be separately sealed from the sealed unit, ormay remain unsealed.

The pump may comprise a dual impellor to move the product. An auxiliaryimpellor may be mounted on the back of a main impellor. The auxiliaryimpellor may be a larger diameter than the main impellor. The auxiliaryimpellor may constitute a hydrodynamic shaft seal and may prevent theflow of the product into the gas seal column during pumping operations.

The drive shaft may be a sleeved shaft to protect the drive shaft fromcorrosion.

In some applications, the pump may require operation at an elevatedtemperature. In those cases where growth in the length of a monolithiccorrosion resistant column might interfere with pump operation, a linedversion of the gas seal column can be used. In FIG. 3 the outer columnmaintains the structural integrity required for reliable pump operationand a two-part telescoping liner maintains the hermetic seal andcorrosion resistance requirements of the application.

Alternatively, if available, and suitable for the application a bellowsliner could be used in place of the telescoping liner.

The pumping system shown in FIG. 1 using the pump drive motor comprisingan extended shaft is for illustration only. A person having ordinaryskill in the art will recognize that various arrangements of the driveshaft may fall within the spirit and scope of the invention as long asthe drive motor is coupled to the pump via the gas seal column.

Referring to FIG. 2, some applications may require a special shaft oflength, diameter, or material of construction not available in anextended shaft pump drive motor. Applications requiring the drive shaftand the gas seal column to be longer may be accomplished by using abearing shaft adapter between the pump drive motor and the gas sealcolumn. The bearing shaft adapter may couple and seal to both the pumpdrive motor and the gas seal column such that the assemblage of the pumpdrive motor, the bearing shaft adapter, the gas seal column, and thepump are sealed. The gas seal column may be of any practical length anddesigned with a plurality of shaft bearing supports and level sensorsalong the length of the gas seal column to satisfy the requirements ofthe application.

The bearing shaft adapter interfaces may be sealed by additional O-ringsto maintain the hermetic seal integrity of the pump drive motor envelopefor those embodiments in which the drive motor is sealed or forms aportion of the single sealed unit. However, in an embodiment in whichthe drive motor is not sealed, additional O-rings are not utilized inthe implementation.

Since a sealed unit encloses a fixed volume of empty space, the sealedunit passively assists in controlling the level of the product trying torise in the gas seal column. Passive assistance may result from BoylesLaw which states that “the pressure of an ideal gas is inverselyproportional to the volume of the ideal gas at a constant temperature”.

P1×V1=P2×V2

where P1 is a first pressure,

V1 is a first volume,

P2 is a second pressure, and

V2 is a second volume.

Simply put—if you halve the available volume of a fixed amount of gasyou will double the pressure.—In accordance with Boyle's Law, as thevolume available for the seal gas is reduced, the pressure of the sealgas increases and the seal gas may become more effective in counteringthe rise of the product.

As experience is gained through the introduction and application of thisinvention consideration should be given to the operational benefits thatmight be optimized by decreasing empty space in the pump drive motorhousing and also the internal shape and size of the gas seal columnaround the drive shaft, all of which may affect system response time.

In an embodiment, the pump device herein described may use a widervariety of readily available unsealed motors as the driving mechanism,which may be use in conjunction with a gas shaft seal for the gas sealcolumn in space 560. A pump having an unsealed motor provides all of theproduct handling features of a fully sealed motor embodiment.

The gas seal column and the pump casing may still be sealed together attheir interface and, in conjunction with a gas shaft seal mounted in thetop mounting panel of the gas seal column. This constitutes a sealedenclosure when the pump drive motor shaft is slid through the gas shaftseal and the pump drive motor is secured to the top mounting panel. Theembodiment is illustrated in FIG. 4 of the drawings.

Turning now to FIG. 1, a cross section of the invention 100 through thepump drive 200, the gas seal column 220, and the pump 270 is shown. Thepump drive 200, the gas seal column 220, and the pump 270 may behermitically sealed to each other. As non-limiting examples, thecircular groove 224 on the top mounting panel 222, the first O-ring 226,the second O-ring 278, the cover plate 280, the pump casing 272, and thethird O-ring 282 may prevent air, the seal gas 208, and the product fromleaking in or out. The pump drive 200 may comprise the drive motor 202and the cooling fan 204.

The gas seal column controls 310, comprising the seal gas control box250, the purge gas valve 254, the first gas valve 256, and the secondgas valve 258, may control the flow of the seal gas 208 into theinvention 100 when activated by the purge gas control switch 252. Theseal gas 208 may be introduced into the gas seal column 220 via the gasinlet pipe connection 230 and may exit the gas seal column 220 via thegas discharge outlet pipe connection 232. The seal gas 208 maypressurize the gas seal column 220 to force the product downwards. Thegas pressure may be regulated by the seal gas control box 250 by openingand closing the purge gas inlet valve 254, the first gas valve 256, andthe second gas valve 258. The gas discharge valve 234 may prevent orpermit the seal gas 208 from exiting the gas seal column 220 and mayalso be under control of the seal gas control box 250. The seal gascontrol box 250 may also control power to the pump drive motor 202 suchthat the seal gas control box 250 may shut down the system if necessary.

The first level sensor 240, the second level sensor 242, the third levelsensor 244, and the fourth level sensor 246 may detect the product levelwithin the gas seal column 220 and may report the product level to theseal gas control box 250.

The drive shaft 214 may turn the main impellor 290 in the pump 270 tomove the product from the inlet 274 to the outlet 276. The auxiliaryimpellor 292 may be coupled to the main impellor 290 and may constitutea hydrodynamic seal to resist the flow of the product into the gas sealcolumn 220. The gas seal column 220 may comprise the plurality ofanti-rotation panels 238 and the plurality of splash quieting discs 236.

Turning now to FIG. 2, a cross section of the invention 100 through thepump drive motor 200, the gas seal column 220, the bearing shaft adapter300, and the pump 270 is shown. The bearing shaft adapter 300 may permitthe introduction of the special shaft 312 when necessary. As anon-limiting example, the additional O-rings 306 may seal the bearingshaft adapter 300 to the pump drive motor 202 and the gas seal column220. The plurality of level sensors 304 may detect the product levelwithin the gas seal column 220 and may report the product level to theseal gas control box 250 as in FIG. 1. The seal gas 208 may flow throughthe invention 100 as described in FIG. 1. As a non-limiting example, theseal gas 208 may enter the gas seal column 220 via the gas inlet pipeconnection 230 and exit at the gas outlet pipe connection 232 aspermitted by the gas discharge valve 234. The seal gas 208 may flowthrough the plurality of shaft bearing supports 302 to push the productlevel down to whatever product level is required for the gas seal column220.

Turning now to FIG. 3, a cross section of the gas seal column with atelescoping liner shows the pump drive motor 400 sealed to the topsection 402 of the telescoping liner and the lower section 404 of thetelescoping liner sealed to the pump casing 408. Both liners are sealedby “O” ring 406 contained in a groove in the top section 402 of theliner and allows for vertically oriented linear telescoping between thetwo liners to allow for thermal expansion and contraction duringtemperature changes. The two-part telescoping liner adjusts verticallythrough a vertical sliding connection between the top section 402 of thetelescoping liner and the lower section 404 of the telescoping linerwhile maintaining integrity against leaks of gas, fluid, or any othermaterial contained within the telescoping liner. All of the telescopingcomponents are contained within structural column 410.

Turning now to FIG. 4, a cross section of an embodiment in which thepump casing 272 is sealed to the lower panel of the gas seal column 520by O-ring 282. The top mounting panel 522 of the gas seal column 520 hasbeen modified to provide space 560 for a gas shaft seal to be used inconjunction with the motor shaft 561 and any type of non-sealed motor502 suitable for the application. With the motor shaft 561 assembledwith the appropriate gas shaft seal and the non-sealed motor 502 securedto the top mounting panel 522, the gas seal column and the pump are asealed unit with an unsealed drive motor 502 attached. The drive shaftcorrosion resistant sleeve 514 has been shortened to allow room for theinclusion of a gas shaft seal. Except for the unsealed drive motor 502such an embodiment will still contain all of the product handlingfeatures of the innovation.

While certain illustrative embodiments have been described, it isevident that many alternatives, modifications, permutations andvariations will become apparent to those skilled in the art in light ofthe foregoing description.

What is claimed is:
 1. A gas seal column apparatus comprising: a pumpdrive motor, a sealed housing further comprising a gas seal column and apump; an auxiliary impellor coupled to a main impeller of said pumpwhere said auxiliary impellor constitutes a hydrodynamic seal; where thegas seal column, and the pump are sealed to one another to comprise asealed, vertically-oriented, pumping system in a sealed pump envelope;where the pump drive motor is connected to said sealed pump envelope;where the gas seal column encases a drive shaft between said drive motorand said pump within said sealed pump envelope and is operable toreplace mechanical seals and packing seals around a drive shaft thatcouples the drive motor to the pump.
 2. The apparatus according to claim1 where the gas seal column comprises gas inlet pipe connection throughwhich the seal gas enters the gas seal column; where the seal gascomprises a gas outlet pipe connection through which the seal gas exitsthe gas seal column via a purge gas discharge valve; where the seal gaswithin the gas seal column displaces the corrosive fumes and theproduct; where pressure of the seal gas is increased and decreased tocontrol a product level within the gas seal column.
 3. The apparatusaccording to claim 2 where the gas seal column comprises a plurality oflevel sensors which detect the product level within the gas seal column;where the plurality of level sensors are positioned at differing heightswithin the gas seal column.
 4. The apparatus according to claim 3 wherethe plurality of level sensors comprises a first level sensor, a secondlevel sensor, a third level sensor, and a fourth level sensor; where thefirst level sensor is located at the lowest level of the gas seal columnand above the lowest level of product needed for the pump to prime andwhen activated signals that the product has entered the gas seal columnand the pump is primed for operation; where the second level sensor islocated above the first level sensor and when activated signals that anincrease in the pressure of the seal gas is needed; where the thirdlevel sensor is located above the second level sensor and when activatedsignals that a further increase in the pressure of the seal gas isneeded and closes the purge gas discharge valve to further aid inincreasing seal gas pressure; where the fourth level sensor is locatedabove the third level sensor and when activated initiates a controlledshutdown of the pump or the entire system.
 5. The apparatus according toclaim 1 further comprising where the gas seal column comprises aplurality of splash quieting discs, a plurality of anti-rotation panels,or combinations thereof to control motion of the product within the gasseal column.
 6. The apparatus according to claim 3 a seal gas controlbox to monitor the product level, to report the product level, and tocontrol the product level and the continued operation of the pump; wherethe seal gas control box monitors the product level via inputs from theplurality of level sensors.
 7. The apparatus according to claim 6 wherethe seal gas control box controls the product level by opening andclosing a purge gas valve, a first gas valve, a second gas valve, thepurge gas discharge valve, or combinations thereof.
 8. The apparatusaccording to claim 1 where the pump comprises, an auxiliary impellorcoupled to a main impellor; where the auxiliary impellor is larger indiameter than the main impeller; where the auxiliary impellor is locatedcloser to the gas seal column than the main impeller; where theauxiliary impellor is operable as a hydrodynamic shaft seal to preventthe flow of the product into the gas seal column during pumpingoperations.
 9. The apparatus according to claim 1 where the pump drivemotor comprises a sealed motor or unsealed motor suitable to drive saidpump.
 10. The apparatus according to claim 9, where the pump drive motorcomprises any style of motor suitable to drive a pump and the topmounting panel of the gas seal column is modified to accept a gas shaftseal, where said gas shaft seal fully seals the gas seal column and pumpenvelope combination.
 11. The apparatus according to claim 3, furthercomprising a sealed, telescoping lined gas seal column for elevatedtemperature conditions where the gas seal column pump comprises a pumpdrive, a gas seal column with telescoping liner, and a pump; where adrive motor of the pump drive, the gas seal column, and the pumpcompromise a sealed, vertically-oriented, pumping system; where said gasseal column liner is sealed, telescoping lined gas seal column forelevated temperature conditions that adjusts vertically in response toelevated temperature operations; where said gas seal column liner iscorrosion resistant; where the gas seal column is operable to replacemechanical seals and packing seals around a drive shaft that couples thedrive motor to the pump.